This invention relates to methods for treating inflammatory diseases by administration of a thrombin inhibitor.
Anti-inflammatory drugs include non steroidal anti-inflammatory drugs (NSAIDs) which exert anti-inflammatory, analgesic and antipyretic activity. These include salicylates such as aspirin, sodium salicylate, choline salicylate, salicylsalicylic acid, diflunisal, and salsalate; indoleacetic acids such as indomethacin and sulindac; pyrazoles such as phenylbutazone, oxyphenbutazone; pyrrolealkanoic acids such as tolmetin; phenylacetic acids such as ibuprofen, feroprofen, flurbiprofen, and ketoprofen; fenamates such as mefanamic acid, and meclofenamate; oxicams such as piroxicam; and naphthaleneacetic acids such as naproxen. Nearly all act by inhibiting cyclo-oxygenase activity. Aspirin, for example, acetylates and irreversibly inactivates cyclo-oxygenase. Others, such as indomethacin, inhibit cyclo-oxygenase activity reversibly by binding in a stereospecific manner to one or another subunit of the enzyme. NSAIDs are active in reducing the prostaglandin-induced pain and swelling associated with the inflammation process but are also active in affecting other prostaglandin-regulated processes not associated with the inflammation process. Thus, use of high doses of most common NSAIDs can produce severe side effects, including life threatening ulcers, that limit their therapeutic potential.
Adrenal corticosteroids, which are alternatives to NSAIDs for treating inflammatory diseases, have even more drastic side effects, especially when long term therapy is involved. These steroids, including hydrocortisone, prednisolone, 6 alpha-methylprednisolone, triamcinolone, dexamethasone and betaroethasone, affect inflammation by a possible mechanism whereby they bind to intracellular glucocorticoid receptors to subsequently initiate a series of cellular events involving synthesis of new phospholipid inhibitory proteins, or lipocortins, that can affect the inflammatory and the teratogenic responses of certain cells exposed to glucocorticoids. The anti-inflammatory effect of glucocorticoids has been well documented.
Excessive bleeding disorders are associated with development of inflammatory conditions. Hemophilia, a bleeding disorder caused by a deficiency clotting Factor VIII or clotting Factor IX, can result in recurring bleeding into joints and muscles that causes crippling inflammation and deformities. Hemophilia also causes swelling of the base of the tongue until it blocks the airway.
Thrombin inhibitors are known to be useful for treating or preventing venous thromboembolism (e.g. obstruction or occlusion of a vein by a detached thrombus; obstruction or occlusion of a lung artery by a detached thrombus), cardiogenic thromboembolism (e.g. obstruction or occlusion of the heart by a detached thrombus), arterial thrombosis (e.g. formation of a thrombus within an artery that may cause infarction of tissue supplied by the artery), atherosclerosis (e.g. arteriosclerosis characterized by irregularly distributed lipid deposits) in mammals, and for lowering the propensity of devices that come into contact with blood to clot blood, but have not been recognized as useful for treating inflammatory diseases.
As described below, it has now been found that thrombin inhibitors, which inhibit formation of blood clots, are in fact effective for inhibiting inflammation.